Objective To study the diagnostic value of MRI for pulmonary embolism, so as to provide information for clinical decision. Methods The trials about MRI in the diagnosis of pulmonary embolism were searched in the following databases such as PubMed, EMbase, The Cochrane Library, CBM, CNKI and VIP. The data of the included trials were extracted, the methodological quality was evaluated in accordance with the quality assessment of diagnostic accuracy studies (QUADAS), and then meta-analysis was conducted using Meta-Disc 1.4 software. The weighted sensitivity and specificity were aggregated, as well as the summary receiver operating characteristic (SROC) curve. Further, the area under the curve (AUC) was calculated to evaluate the value of MRI in the diagnosis of pulmonary embolism. Results A total of 6 English articles involing 595 patients were included. The results of heterogeneity test revealed that there was statistical heterogeneity among the results of studies. According to the random effects model, the weighted sensitivity and specificity were 0.87 (95%CI 0.80 to 0.91), and 0.98 (95%CI 0.96 to 0.99), respectively; and the AUC was 0.988 7. Conclusion MRI is a better non-invasive method as a routine examination for pulmonary embolism. It shows fairly high sensitivity and specificity, and has a good clinical value.
目的 探讨膝关节盘状半月板的诊断标准，双膝盘状半月板的MRI分型及损伤特点。 方法 通过对2009年11月－2013年3月，13 936膝大样本量的MRI检查的盘状半月板流行病学研究，筛查出双膝关节盘状半月板956膝，并对诊断为盘状半月板的全部患者行冠状位髁间棘层面半月板宽度与胫骨平台宽度之比（板面比）、矢状位“领结样”改变层面中半月板后角最厚层面的厚度（半月板后角厚度）及矢状位“领结样”改变层数测量并分析；根据盘状半月板MRI表现分为板型、楔型、肥角型；分析双膝盘状半月板分型，比较双膝盘状半月板损伤率与总体损伤率的差别。 结果 956膝盘状半月板中伴撕裂392膝，损伤率为41.0%；筛查出45例90膝双膝盘状半月板，外侧44例，内侧1例，其中板型58膝、楔型32膝，无肥角型，伴盘状半月板撕裂23膝，损伤率为25.5%；双膝盘状半月板的损伤率低于盘状半月板总体平均值。 结论 板面比≥0.20、半月板后角厚度≥4.40 mm、矢状位连续“领结样”改变层数≥3层为盘状半月板的MRI诊断标准；双膝盘状半月板多见于外侧，分型中未见肥角型，损伤率较总体损伤率低。
目的 探讨囊性脑膜瘤的磁共振表现、表观弥散系数（ADC）图的影像特点、ADC值与病理分级的关系及ADC值对判断不同病理亚型脑膜瘤的价值。 方法 回顾性分析2003年3月－2007年12月18例经病理证实的囊性脑膜瘤患者的磁共振表现，其中男8例，女10例，平均年龄45.6岁。在ADC图上分别测量肿瘤实质、瘤周水肿、囊变区的平均ADC值（均取4～6个区域，取平均值），比较不同病理亚型、不同病理分级的肿瘤实质、瘤周水肿、囊变区的ADC值差异是否有统计学意义。 结果 良恶性脑膜瘤肿瘤实质ADC值差异无统计学意义（P＞0.05）；囊性脑膜瘤各亚型间的肿瘤实质、瘤周水肿的ADC值差异无统计学意义（P＞0.05）；肿瘤实质、囊变区与瘤周水肿平均ADC值相比差异均有统计学意义（P＜0.05）。 结论 ADC值可区分肿瘤实质、囊变区及瘤周水肿，但对脑膜瘤亚型及良恶性的甄别需结合常规MRI与增强的征象。Objective To explore the MRI imaging manifestation, features of apparent diffusion coefficient (ADC) map and the relationships among ADC value, pathologic grading and pathologic subtype of cystic meningioma. Methods The clinical data of 18 patients (8 males and 10 females, with an average age of 45.6 years) with cystic meningiomas confirmed by pathologically examination were retrospectively analyzed. The ADC values of tumor parenchyma, peritumoral edema, cystic regions and the contralateral normal brain of the tumor parenchyma were measured and analyzed.The ADC value of the tumor parenchyma, peritumoral edema, cystic region were measured and then compared with the pathological findings. P value of less than 0.05 was considered as having a statistically significant difference. Results There was no significant difference in ADC values between benign and malignant meningioma and also among the tumor parenchyma, periedema and cystic region in different pathological subtypes. The difference in ADC values amongst tumor parenchyma, peritumoral edema and cystic region were statistically significant (P＜0.05). Conclusions Although ADC quantitative measurement allows the differentiation of the tumor parenchyma, cystic region and peri-edema, it is need to combined with conventional MR examination to assess tumor malignancy as well as grading in cystic meningioma.
【摘要】 目的 优化牙釉质电子顺磁共振（EPR）谱拟合程序。 方法 将牙釉质EPR谱拟合程序中的RIS-BGS偏移量设置为定参，取优化值；增加手动拟合功能，可以将参数初始值直接代入高斯模型得到拟合谱。 结果 将牙釉质EPR谱拟合程序中RIS-BGS偏移量设置为定参后，其优化值为0.529，减少了变参数量；采用手动拟合功能有助于调整参数初始值；在自动拟合程序对于个别样品谱不能给出正确结果情况时，仍然可以通过手动拟合来得到一个近似的拟合结果。 结论 优化了EPR谱拟合程序的应用过程。【Abstract】 Objective To optimize the enamel electron paramagnetic resonance (EPR) spectrum fitting procedure. Methods RIS-BGS offset was set as a determined parameter in enamel EPR spectrum fitting program, and an optimized value was given for RIS-BGS offset. A manual fitting function was designed that can substite the initutial value into the Gaussian model function directly. Results RIS-BGS offset was set as a determined parameter, the optimized value of which was 0.529. The number of parameters decreased; the manual fitting function maked it easier to select initial values for parameters. When the auto fitting program failed to give a correct result for some EPR spectrum, a fitting result could still be obtained with the manual fitting method. Conclusion The application of the spectrum fitting procedure can be optimized.
目的:通过分析平山病的磁共振成像(MRI)表现特点和结合文献复习，提高其诊断水平。方法:报道1例经临床证实的平山病患者的MRI表现，并复习文献，探讨MRI表现的相关发病机制及病理解剖基础。结果:采用西门子Sonata 1.5T磁共振机，先取生理状态下颈椎MRI检查，显示脊髓前角非对称性萎缩和脊髓背侧硬膜外静脉丛扩张；再行屈颈状态下MRI检查，可见颈髓的硬脊膜后壁向前推移，下段颈髓局限受压变细征。结论:平山病有特征性MRI表现，结合临床、常规位和功能位屈颈状态的MRI检查，可以提示平山病。
Objective To assess the clinical efficacy of neoadjuvant chemotherapy （NAC） for breast invasive ductal carcinoma with MR diffusion weighted imaging. Methods Thirty patients with breast invasive ductal carcinoma underwent conventional MRI scanning and diffusion weighted imaging examination before and after preoperative neoadj-uvant chemotherapy. Two experienced radiologists independently analyzed and measured the maximum lesion diameter and apparent diffusion coefficient （ADC） values before and after treatment，respectively. Statistical analysis was performed for testing the tumor maximum diameter and ADC values change by using the paired t-test. Results After NAC treatment，the maximum tumor diameter of invasive ductal breast carcinoma sharply reduced〔（4.33±0.83） cm vs. （2.04±0.64） cm，P＜0.001〕. When b value was 1 000，the mean ADC values of breast massess were significantly changed after NAC treatment〔（1.89±0.15） ×10-3mm2/s vs. （1.14±0.31） ×10-3mm2/s， P＜0.05〕. Conclusion MR diffusion weighted imaging can non-invasively and accurately assess the NAC efficacy， which are helpful for making surgical strategies.
Objective To summarize and analyze the MRI imaging findings of advanced gastric cancer in order to improve the level of image diagnosis. Methods The plain and dynamic enhanced MRI findings in 8 volunteers and 30 patients with pathologically proven advanced gastric cancer were retrospectively analyzed. Results The stomach wall of advanced gastric cancer was inhomogeneous thickening with iso intensity or little hypo intensity signal on T1WI， and iso intensity or little hyper intensity signal on T2WI. Cases with serosal infiltration， the serous appearred indistinctly and rough. In some cases， the low signal zones between gastic wall and fat space were interrupted on T1WI out-of-phase image. Cases with adjacent organs invaded， the fat space was rough or disappeared. The lesions showed obvious irregular or hierarchy enhancement on MRI dynamic contrast scanning. Conclusions Inhomogeneous thickening of gastic wall with abnormal signal intensity， indistinctness or disappearance of fat space， irregular or hierarchy enhancement are very valuable as diagnostic signs in patients suspective of advanced gastric cancer.
ObjectiveTo investigate the feasibility of proton magnetic resonance spectroscopy (1H-MRS) imaging, by which to quantitatively analyze liver fat content for therapeutic evaluation of fatty liver at 3.0 T MRI. MethodsTwenty-six patients who diagnosed with fatty liver were examined with proton MRS at Siemens Trio Tim 3.0 T MRI before treatment and 3, 6 months after treatment, respectively. The water peak, fat peak, water peak area, and fat peak area were detected, and the relative lipid content 1 (RLC1) and relative lipid content 2 (RLC2)were calculated. Fatty liver index (FLI) was referred to the standard which was calculated from triglycerides (TG), gammaglutamyl-transferase (GGT), waist circumference, and body mass index. ResultsThere were significantly different differences of RLC1 and RLC2 among before treatment and 3, 6 months after treatment (Plt;0.05). Compared with before treatment, the RLC1 and RLC2 values significantly decreased on month 3 or 6 after treatment (Plt;0.05). There were positive correlation between RLC1 or RLC2 and FLI (r=0.476, Plt;0.00; r=0.475, Plt;0.001). The intraclass correlation coefficient was more than 0.75 before treatment, the repeatability was better. ConclusionsProton MRS can quantitatively measure liver fat content. It can be reliably used for dynamic monitoring the therapeutic effects for fatty liver. Proton MRS is accurate, and has a good clinical application in dynamically monitoring the progression of fatty liver and evaluating the therapeutic effects of various treatments.